1. Field of Invention
The present invention relates to a pixel structure. More particularly, the present invention relates to a pixel structure having a mechanism for repairing possible shortcircuits between a scan line and a data line.
2. Description of Related Art
With the rapid advance in semiconductor technologies and man-machine interface designs, multi-media are now at the forefront of communication. In a multi-media world, displays are important devices. Although the cathode ray tube (CRT) is economical to produce and has advantages in many aspects, possible production of hazardous radiation, a bulky body and enormous power consumption are three major factors that diminish its desirableness in a multi-terminal desktop environment. With better resolution, space utilization and power consumption, the thin film transistor liquid crystal display (TFT-LCD) has been developed to serve as a substitute the CRT.
FIG. 1 is a schematic top view of a conventional pixel structure repaired through a laser chemical vapor deposition (CVD). As shown in FIG. 1, a conventional pixel structure 100 comprises a scan line 102, a data line 104, a thin film transistor 106 and a pixel electrode 108. The thin film transistor 106 furthermore comprises a gate 106a, a channel layer 106b and a source/drain 106c. The gate 106 and the scan line 102 are electrically connected together. Similarly, the source/drain 106c, the data line 104 and the pixel electrode 108 are electrically connected together.
The scan line 102 is part of a first metallic layer (metal 1) and the data line 104 is part of a second metallic layer (metal 2). Hence, the scan line 102 and the data line 104 are electrically isolated from each other through a first dielectric layer (a gate insulation layer). In addition, a second dielectric layer (a passivation layer) is also formed over the data line 104. However, a short circuit in the cross over region between the scan line 102 and the data line 104 is possible due to some defects in the dielectric layer, e.g., impurities or particles contamination. Most short-circuits between the scan line 102 and the data line 104 can be repaired. To repair the short circuit, the data line 104 at both ends of a short-circuited region is severed (as shown by the dash line). Thereafter, two repair openings 110 are formed in the second dielectric layer. A laser chemical vapor deposition (CVD) process is performed to form a thin metallic layer 112 linking up the severed data line 104 through the repair openings 110. In other words, the severed data line 104 is reconnected after the reparation.
In a conventional laser repair, the thin metallic line 112 must cross over the scan line 102 to link up both ends of the severed data line 104. Thus, the thin metallic line 112 usually has a considerable length resulting in a longer and costlier repair.